Brain Pathology Case of the Month - March 2003

*Department of Neurology, University of Tübingen, Medical School, Tübingen, Germany; +Department of Neuropathology, University of the Saarland, Homburg, Germany and the $ Department of Surgery, Civic Hospital Esslingen, Germany

Published on line in March 2003

CLINICAL HISTORY:

A 41 year old woman presented in 1997 with diffuse abdominal pain, meteorism and intermittent diarrhea. Gastrointestinal workup including abdominal computed tomography (CT) and magnetic resonance imaging (MRI) scans revealed a focal rounded lesion in segment IV of the liver without any edema or reactive changes. Although there was no history of progesterone or estrogen therapy, the radiographic appearance was considered to be suggestive of adenoma (Figure 1, arrow). The lesion was monitored by ultrasound until October 2000 when a resection of hepatic segment VI was performed because of the presumed risk of a malignant transformation.

PATHOLOGICAL FINDINGS:

The lesion was excised and intraoperatively found to be surrounded by 3 smaller satellite nodules, located close to the liver capsule, the parietal peritoneum and infiltrating the diaphragm. Histological examination of H&E stained sections revealed a densely cellular tumor with fibrillarity and arrangement of the tumor cells around blood vessels with a distinctive fibrillar, anuclear zone (Figure 2). Immunohistochemistry was negative for protein S-100, synaptophysin, neurofilament protein, microtubule-associated protein 2C (MAP2C) and chromogranin A, but strongly positive for glial fibrillary acidic protein (GFAP) (Figure 3). The surrounding hepatic tissue was negative for GFAP. Mitotic activity was not observed.

The patient was referred for further evaluation and assessment of a primary CNS lesion, in the absence of clinical evidence of neurological disease. An extensive search for a CNS manifestation or any other extraspinal localization was unrevealing, including craniospinal and thoracoabdominopelvic MRI and cerebral spinal fluid analysis. Radiographically, there was modest hyperplasia of the thymus of uncertain significance. Whole body scintigraphy as well as clinical chemistry was unremarkable.